U.S. patent number 10,566,956 [Application Number 15/843,102] was granted by the patent office on 2020-02-18 for cascaded transceiver integrated circuit.
This patent grant is currently assigned to NXP B.V.. The grantee listed for this patent is NXP B.V.. Invention is credited to Ralf Reuter.
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United States Patent |
10,566,956 |
Reuter |
February 18, 2020 |
Cascaded transceiver integrated circuit
Abstract
An apparatus is provided comprising a first integrated circuit.
The first integrated circuit comprises a first element comprising
one of a transmit or receive element, an oscillator for providing a
first local oscillator signal, a local oscillator output configured
to output the first local oscillator signal when activated, a local
oscillator input configured to receive a master local oscillator
signal when activated; and first switching circuitry for
selectively coupling the first element to one of the oscillator and
the local oscillator input.
Inventors: |
Reuter; Ralf (Landshut,
DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
NXP B.V. |
N/A |
N/A |
N/A |
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Assignee: |
NXP B.V. (Eindhoven,
NL)
|
Family
ID: |
57714423 |
Appl.
No.: |
15/843,102 |
Filed: |
December 15, 2017 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
|
US 20180175831 A1 |
Jun 21, 2018 |
|
Foreign Application Priority Data
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|
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Dec 21, 2016 [EP] |
|
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16205828 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01S
7/032 (20130101); G01S 13/87 (20130101); H01Q
1/2283 (20130101); G01S 7/35 (20130101); H03K
5/14 (20130101); H03K 3/01 (20130101); G01S
7/038 (20130101); G01S 13/931 (20130101); H01Q
9/0407 (20130101); G01S 7/4017 (20130101); G01S
7/034 (20130101); G01S 2013/93275 (20200101) |
Current International
Class: |
H03K
3/01 (20060101); H03K 5/14 (20140101); G01S
7/03 (20060101); G01S 7/40 (20060101); G01S
7/35 (20060101); G01S 13/931 (20200101); H01Q
1/22 (20060101); G01S 13/87 (20060101); H01Q
9/04 (20060101); G01S 13/93 (20200101) |
Field of
Search: |
;331/74 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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102016101318 |
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Aug 2016 |
|
DE |
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2016/054291 |
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Apr 2016 |
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WO |
|
Primary Examiner: Chang; Joseph
Attorney, Agent or Firm: Madnawat; Rajeev
Claims
The invention claimed is:
1. An apparatus comprising a first integrated circuit comprising: a
transmit element; a receive element; an oscillator configured to
provide a first local oscillator signal; a local oscillator output
configured to output the first local oscillator signal when
activated; a local oscillator input configured to receive a master
local oscillator signal when activated; a first plurality of select
buffers configured to selectively couple the transmit element and
the receive element to the oscillator; and a second plurality of
select buffers configured to selectively couple the local
oscillator input to the oscillator, the receive element, and the
transmit element.
2. The apparatus of claim 1, wherein the first integrated circuit
is a master integrated circuit and the local oscillator is
configured to output the first local oscillator signal as the
master local oscillator signal.
3. The apparatus of claim 2, wherein the local oscillator input is
activated to receive the master local oscillator signal.
4. The apparatus of claim 1, further comprising: a delay line
external to the first integrated circuit connected between the
local oscillator output and the local oscillator input.
5. The apparatus of claim 4, wherein an electrical delay length of
the delay line corresponds to a distance of the first element to a
first unwanted reflection received by the first element.
6. The apparatus of claim 1, wherein the first element is an
antenna for a radar system.
7. The apparatus of claim 1, wherein the first plurality of select
buffers comprises a first select buffer and a second select buffer
that are configured to selectively couple the oscillator to the
transmit element.
8. The apparatus of claim 7, wherein the first plurality of select
buffers further comprises a third select buffer that is configured
to selectively couple the oscillator to the receive element in
combination with the first select buffer and the second select
buffer.
9. The apparatus of claim 8, wherein the second plurality of select
buffers comprises a fourth select buffer that is configured to be
selectively coupled to the receive element.
10. The apparatus of claim 9, wherein the second plurality of
select buffers further comprises a fifth select buffer that is
configured to selectively couple the fourth select element to the
transmit element.
11. The apparatus of claim 1, wherein the transmit element is
coupled directly to the oscillator.
12. The apparatus of claim 1, wherein the second external port is
coupled to the receive element via a buffer that is configured to
act as an input amplifier.
13. A system comprising: a first integrated circuit comprising: a
first transmit element; a first receive element; a first voltage
controlled oscillator configured to provide a first local
oscillator signal; a first local oscillator output configured to
output the first local oscillator signal when activated; a first
local oscillator input configured to receive a master local
oscillator signal when activated; and a first plurality of select
buffers configured to selectively couple the first transmit element
and the first receive element to the first voltage controlled
oscillator; and a second plurality of select buffers configured to
selectively couple the first local oscillator input to the voltage
controlled oscillator, the first receive element, and the first
transmit element; and a second integrated circuit comprising: a
second transmit element; a second receive element; a second voltage
controlled oscillator configured to provide a second local
oscillator signal; a second local oscillator output configured to
be deactivated; a second local oscillator input configured to be
activated to receive the master local oscillator signal; a third
plurality of select buffers configured to selectively couple the
second transmit element and the second receive element to the
second voltage controlled oscillator; and a fourth plurality of
select buffers configured to selectively couple the second local
oscillator input to the voltage controlled oscillator, the second
receive element, and the second transmit element.
14. The system of claim 13, wherein the system is a radar
system.
15. The system of claim 13, wherein the element is an antenna
element.
16. The system of claim 15, wherein the first element is one of a
planar patch antenna and/or 3D integrated antenna.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the priority under 35 U.S.C. .sctn. 119 of
European Patent application no. 16205828.3, filed on Dec. 21, 2016,
the contents of which are incorporated by reference herein.
FIELD
The present application relates to radar transceivers and in
particular but not exclusively to the implementation of multiple
integrated circuits in a radar system.
BACKGROUND
In radar systems, a radar front end integrated circuit may be
provided. This front end integrated circuit (IC) may comprise a
plurality of receive and/or transmit elements and be configured to
receive or transmit radio frequency (RF) radar signals. The
operation of the receive and/or transmit elements may be
synchronised in order to provide a phase coherent system. In order
to facilitate this, a common oscillator signal may be shared
between the elements.
SUMMARY
According to a first aspect of the present application, there is
provided an apparatus comprising a first integrated circuit
comprising: a first element comprising one of a transmit or receive
element; a oscillator for providing a first local oscillator
signal; a local oscillator output configured to output the first
local oscillator signal when activated; a local oscillator input
configured to receive a master local oscillator signal when
activated; and first switching circuitry for selectively coupling
the first element to one of the oscillator and the local oscillator
input.
The first integrated circuit may be a master integrated circuit and
the local oscillator is activated to output the first local
oscillator signal as the master local oscillator signal. The local
oscillator input may be activated to receive the master local
oscillator signal. The first switching circuitry may be configured
to couple the first element to the local oscillator input. The
first integrated circuit may further comprise a second element
comprising one of a transmit and receive element and second
switching circuitry for selectively coupling the second element to
one of the local oscillator input and the oscillator. The second
switching circuitry may be configured to couple the second element
to the oscillator.
The apparatus may further comprising a delay line with the local
oscillator output and local oscillator input, the delay line being
external to the first integrated circuit. The electrical delay
length of the delay line may correspond to a distance of the first
element to a first unwanted reflected received by the first
element. The first switching circuitry may be configured to couple
the first element to the oscillator. The element may be an antenna
for a radar system.
According to a second aspect, there is provided a system
comprising: a first integrated circuit comprising: a first element
comprising one of a transmit or receive element; a oscillator for
providing a first local oscillator signal; a local oscillator
output configured to output the first local oscillator signal when
activated; a local oscillator input configured to receive a master
local oscillator signal when activated; and first switching
circuitry for selectively coupling the first element to one of the
oscillator and the local oscillator input; and at least one further
integrated circuit comprising: at least one first element
comprising one of a transmit or receive chain; a voltage controlled
oscillator for providing a further local oscillator signal; a local
oscillator output configured to be deactivated; a local oscillator
input configured to be activated to receive the master local
oscillator signal; and a switch for selectively coupling the at
least one first element to the local oscillator input.
The system may be a radar system. The element may be an antenna
element. The element may be one of a planar patch antenna and/or 3D
integrated antenna. The oscillator may be a voltage controlled
oscillator.
FIGURES
Embodiments will be described, by way of example only, with
reference to the drawings, in which:
FIG. 1 is a schematic diagram of a first example implementation of
an embodiment;
FIG. 2 is a schematic diagram of a second example implementation of
an embodiment;
FIG. 3 is a schematic diagram of a third example implementation of
an embodiment;
FIG. 4 is a schematic diagram of a fourth example implementation of
an embodiment;
FIG. 5 is a schematic diagram of a fifth example implementation of
an embodiment; and
FIG. 6 is a schematic diagram of an example implementation of
on-chip circuity.
It will be appreciated that for features that span more than one
drawing like reference numerals indicate the like feature.
DETAILED DESCRIPTION
Radar transceivers implemented on an integrated circuit may
typically be implemented for a specific application and may not be
difficult to adapt to be used for various other applications.
Embodiments of the present application present a radar system in
which a plurality of integrated circuits, each comprising receive
and/or transmit circuitry, may be cascaded to form an adaptable
system. A local oscillator signal may be generated and cascaded
through the plurality of integrated circuit in a manner that is
phase consistent.
In embodiments an integrated circuit is provided comprising an
element, for example a receive element and/or a transmit element
and a signal generator, for example an oscillator. The oscillator
may be capable of providing a first local oscillator signal when
activated. The integrated circuit may further have a local
oscillator output port which, when activated, will provide the
first local oscillator signal to circuitry external to the
integrated circuit (off-chip). The local oscillator output port may
be activated by coupling it to the output of the oscillator. The
integrated circuit may also comprise a local oscillator input port
which, when activated, will receive a master local oscillator
signal from circuitry external to the integrated circuit
(off-chip). The first element can be selectively coupled to receive
an oscillator signal from the oscillator or the local oscillator
input port. If further elements are on the integrated circuit, they
may also be selectively coupled to receive an oscillator signal
directly from the oscillator or from the local oscillator input
port.
The integrated circuit may be adjustable in that it may generate a
master local oscillator signal for the radar system by activating
the local oscillator output port. In this case, the integrated
circuit will be a master integrated circuit. Elements, for example,
transmit and/or receive elements, on the master integrated circuit
may receive an oscillator signal directly from the oscillator or
via the local oscillator input port which may be coupled to the
local oscillator output port to receive the master local oscillator
signal. Connecting the local oscillator input port to the local
oscillator output port means that, if required, delay elements may
be introduced into the connection as it is external to the
integrated circuit. This may be useful in some modes of
operation.
The radar system may comprise a plurality of integrated circuits. A
master integrated circuit will provide a master local oscillator
signal to one or more slave integrated circuits. The master local
oscillator signal may be provided to local oscillator input ports
of the slave integrated circuits and provided to elements on the
slave integrated circuit.
Delay elements may be introduced in a path between a master local
oscillator output port and the local oscillator input ports in
various embodiments. The integrated circuits may be cascaded while
having a master local oscillator signal generated by an oscillator
of a master integrated circuit. It will be appreciated that as the
local oscillator input ports, local oscillator output ports,
elements and oscillators of the system may be selectively connected
to each other, a variety of cascaded configurations are possible.
Some examples of configurations are discussed in relation to FIGS.
1 to 5.
FIG. 1 shows a first example configuration of an integrated circuit
comprising a transmit and a receive element in accordance with an
embodiment. The integrated circuit 100 may be cascaded with other
integrated circuits to form a radar transceiver system, however in
this example, the integrated circuit 100 is implemented
individually.
An element may be an antenna for the radar system and for a receive
element, may be configured to receive radar signals and for a
transmit element, be configured to transmit radar signals. The
antennas may be directly coupled to a radar signal input or output.
In some examples, the antenna may be for example, planar patch
antenna and/or 3D integrated antenna.
The integrated circuit 100 comprises a receive element 101 and a
transmit element 102. The integrated circuit further comprises an
oscillator. The oscillator may comprise a voltage controlled
oscillator.
The integrated circuit 100 comprises a local oscillator output port
104 and a local oscillator input port 105. The local oscillator
output port 104 may be configured to be coupled to an output of the
oscillator 103 when the local oscillator output port 104 is
activated. In this case, the local oscillator output port 104 is
activated and is coupled to the oscillator 103 via a buffer 106 on
the integrated circuit 100.
The buffer 106 may provide gain and output power to allow
sufficient drive level to an external component (in this example,
the delay line 108), the buffer 107 may act as input amplifier to
provide gain and power to the internal circuit (in this case, the
receive element 101). It will be appreciated that the
implementation of such buffers is optional and they may be absent
in some implementations. The elements 102 and 101 may be
selectively coupled to either the oscillator 103 or to the local
oscillator input port 105. In this example, the transmit element
102 is coupled directly to the oscillator 103 with a connection on
the integrated circuit 100. The receive element 101 is coupled to
the local oscillator input port 105 via a buffer 107 on the
integrated circuit 107.
The local oscillator output port 104 is coupled to the local
oscillator input port 105 and provides a local oscillator signal
from the oscillator 103 to the local oscillator input port 105. In
this case, the oscillator is coupled to provide a local oscillator
signal externally to the integrated circuit 100 and the integrated
circuit 100 is a master integrated circuit providing a master local
oscillator signal from the master oscillator. The local oscillator
input port 105 received the master local oscillator signal and
provides it to the receive element 101.
The connection between the local oscillator output port 104 and
local oscillator input port 105 is external to the integrated
circuit 100 and an external delay element 108 may be introduced
between the two. This may be implemented in, for example, a systems
where a radar sensor is mounted behind a bumper. In this case
strong reflections from the bumper will degrade the sensor
sensitivity and will affect the detection of close objects (for
example in parking applications). Splitting the connection of the
local oscillator signal between the transmit and receive elements,
allows and an external delay line to be introduced to the receive
element 101. This delay may be configured to mitigate the strong
bumper reflection which may enable a higher signal to noise ratio
(SNR) for close objects. In some examples, the delay line 108 may
be of few millimetres such that the length of the electrical delay
may correspond to a distance between the antenna to a major
unwanted reflection--in this example, the bumper.
While FIG. 1 shows an implementation of the invention on a single
integrated circuit, it will be appreciated that in other examples,
a plurality of integrated circuits may be cascaded with one of the
integrated circuits acting as a master integrated circuit. FIG. 2
gives one such example.
In the example of FIG. 2, a master integrated circuit 100 is
configured similarly to the integrated circuit as described in
relation to FIG. 1. In this regard it will be appreciated that like
reference numerals depict like features.
The radar system 200 of FIG. 2 comprises a master integrated
circuit 100 and a first slave integrated circuit 210, second slave
integrated circuit 220 and third slave integrated circuit 230. Each
of the slave circuits comprise a frequency generating element (for
example oscillator 103), transmit element and receive element. Each
of the slave integrated circuits further comprise a local
oscillator output port and local oscillator input port. In the
example of FIG. 2, the master integrated circuit 100 provides a
master local oscillator signal at the master local oscillator
output port 104.
The master oscillator signal may be provided to the local
oscillator input ports of each of the slave integrated circuits.
The slave integrated circuit may be configured to couple their
local oscillator input ports to provide the master local oscillator
signal to their receive and transmit elements. The local oscillator
output ports of the respective slave integrated circuits may be
deactivated. In some examples, the oscillators of each of the slave
integrated circuits are also deactivated. In other examples, the
oscillators may be used for other functions on the integrated
circuit and are only deactivated with respect to the transmit and
receive elements.
In this example, the master integrated circuit and slave integrated
circuit may be phase coherent. The master oscillator signal
received at each respective input of the plurality of elements
across the integrated circuits may be phase coherent. This may be
due to the local oscillator input port 105 of the master integrated
circuit 100 receiving the master oscillator signal that has been
routed from the local oscillator output port 104 of the master
integrated circuit. This routing external to the integrated circuit
may introduce a delay that is equal to the delay caused by the
routing of the master local oscillator signal to the slave
integrated circuits. The elements may all received a phase coherent
local oscillator signal. In this example, the delay line 108 at the
master integrated circuit may be set to be equal to the delay
incurred by the connection between the master local oscillator
output port 104 and the local oscillator input ports of the slave
integrated circuits 210, 220 and 230.
FIG. 3 shows another example configuration of cascaded integrated
circuits in a radar system. FIG. 3 shows a master integrated
circuit 300 and a slave integrated circuit 310. The master
integrated circuit 300 comprises a transmit element 301, a receive
element 302, a oscillator 303, a local oscillator output port 304
and a local oscillator input port 305. The slave integrated circuit
310 comprises a transmit element 311, a receive element 312, a
oscillator 313, a local oscillator output port 314 and a local
oscillator input port 315.
In this example, the local oscillator output port 304 of the master
integrated circuit is activated to provide a master local
oscillator signal externally to the master integrated circuit 300.
The local oscillator port 304 of the master integrated circuit 300
is coupled to the oscillator 303. The transmit and receive elements
301 and 302 of the master integrated circuit are coupled to the
local oscillator input port 305 which is activated to provide the
master local oscillator signal.
On the slave integrated circuit 310, the oscillator 313 and the
local oscillator output port 314 may be deactivated. The transmit
and receive elements 311 and 312 of the slave integrated circuit
310 may be coupled to the local oscillator input port 315 which is
activated to provide the master local oscillator signal to the
transmit and receive elements 311 and 312.
The master oscillator signal may be routed from the local
oscillator output port 304 externally to the integrated circuits
and split at splitter 320. The respective split master oscillator
signals may then be routed back to the respective local oscillator
input ports 305 and 315.
In this examples, the integrated circuit 300 is acting as a master
and providing the master local oscillator signal the master local
oscillator output port 304 to the slave integrated circuit 310. By
feeding the master oscillator signal to one or more slave
integrated circuits in the system via their respective local
oscillator input ports, an internal integrated circuit delay (from
the local oscillator input port to an input of an transmit or
receive element on the integrated circuit) is identical. This may
provide phase coherence over temperature variations.
It will be appreciated that the length of the external coupling
from the power splitter 320 to the respective local oscillator
input ports 315 and 305 should be identical to achieve identical
phase distribution.
While the oscillator 313 of the slave integrated circuit 310 is
deactivated in this example, in other example it may be tuned for
use in other functions.
FIG. 4 shows another example configuration of cascaded integrated
circuits in a system.
FIG. 4 comprises a master integrated circuit 400 and a first 410,
second 420 and third 430 slave integrated circuit.
The master integrated circuit 400 comprises a transmit element 401,
a receive element 402, a oscillator 403, a local oscillator output
port 404 and a local oscillator input port 405. The slave
integrated circuits 410, 420, 430, each comprises a transmit
element, a receive element, a oscillator, a local oscillator output
port and a local oscillator input port.
In this example, the local oscillator output port 404 of the master
integrated circuit is activated to provide a master local
oscillator signal externally to the master integrated circuit 400.
The local oscillator port 404 of the master integrated circuit 400
is coupled to the oscillator 403. The transmit and receive elements
401 and 402 of the master integrated circuit are coupled to the
oscillator output.
For each slave integrated circuit 410, 420, 430 the oscillator and
the local oscillator output port may be deactivated. The transmit
and receive elements of the respective slave integrated circuits
may be coupled to the local oscillator input ports which are
activated to provide the master local oscillator signal to the
transmit and receive elements.
The master oscillator signal may be routed from the local
oscillator output port 404 externally to the integrated circuits
provided to a respective local oscillator input port of each of the
slave integrated circuits 410, 420 and 430.
In this example, the master and slave integrated circuits are not
phase coherent over temperature with respect to the master local
oscillator signal. This may be because the transmit and receive
elements 401 and 402 of the master integrated circuit 400 are
coupled to receive the master local oscillator signal directly from
the oscillator instead of the master local oscillator input port
405. In this examples, the master integrated circuit may be used
for example for elevation measurements. The slave integrated
circuits 410, 420 and 430 in this example are phase coherent with
respect to the master local oscillator signal.
FIG. 5 shows another example of a potential configuration of an
integrated circuit. In the example of FIG. 5, an integrated circuit
is not used for cascaded and the elements of the integrated circuit
receive a local oscillator signal from the oscillator on the
integrated circuit.
The master integrated circuit 500 comprises a transmit element 501,
a receive element 502, a oscillator 503, a local oscillator output
port 504 and a local oscillator input port 505. The local
oscillator output port 504 and the local oscillator input port 505
are deactivated and the transmit element 501 and the receive
element 502 receive a local oscillator signal directly from the
oscillator 503.
FIG. 6 shows an example of switching circuitry that may be
implemented on an integrated circuit 100, 400, 500 in order to
enable the selective connection of an element to a local oscillator
input port or oscillator and an activation of a local oscillator
output port and/or local oscillator input port.
It will be appreciates that some of the circuitry of FIG. 6 may
correspond to circuitry already described and like reference
numerals depict like features.
The integrated circuit 600 of FIG. 6 comprises a local oscillator
output port 104, local oscillator input port 105, oscillator 103,
receive element 101 and transmit element 102. The oscillator 103
may be coupled to the local oscillator output port 104 via a first
select buffer 605, optional amplifying buffer 106 and optional
balun 608. When the local oscillator output port is activated, the
select buffer 605 may be configured to couple the oscillator to the
local oscillator output port.
The oscillator 103 is selectively coupled to the transmit element
102 via the first select buffer 605 and a second select buffer 604.
The first and second select buffers are configured to couple the
oscillator 103 to the transmit element 102 when the transmit
element 102 is to receive an oscillator signal directly from the
oscillator 103.
The oscillator 103 is further selectively coupled to the receive
element 101 via the first select buffer 605, the second select
buffer 604 and third select buffer 603. The first 605, second 604
and third select 603 buffers are configured to couple the
oscillator signal to the receive element 101 when selected.
The receive element 101 and transmit element 102 are further
configured to be coupled to a local oscillator input port 105. The
local oscillator input port 105 may be coupled to a fourth select
buffer 601 via an optional balun 607 and optional amplifying buffer
107. The fourth select buffer 601 may be selectively coupled to the
receive element 101. The fourth select buffer 601 may be
selectively coupled to the transmit element 102 via a fifth select
buffer 602.
In operation, the first to fifth select buffers may be selectively
controlled to couple the oscillator 103, receive element 101 and
transmit element 102 to the local oscillator input and output ports
104, 105 and to the oscillator signal provided by oscillator
103.
While the switching of the integrated circuit has been exemplified
with the use of the first to fifth buffers, it will be appreciated
that other switching circuitry may be implemented.
In the foregoing, an integrated circuit has been depicted as
comprising a local oscillator and receive and transmit elements, it
will be appreciated that an integrated circuit may comprise a
differing configuration of elements in other embodiments. In some
examples, an integrated circuit may comprise only receive elements
or only transmit elements. It will be appreciated that the present
application may be application to integrated circuit having any
combination of receive and transmit elements.
In the foregoing reference has been made to an oscillator. It will
be appreciated that the oscillator may be provided by a suitable
oscillator circuitry, for example a voltage controlled oscillator
or other signal generator.
In the foregoing, a split coupling from a local oscillator output
port to two or more local oscillator input ports has been depicted.
It will be appreciated that the split coupling may be implemented
by any suitable connection. In some examples, the split coupling
may be realized by passive structures such as a Wilkinson divider
or rat-race coupler.
* * * * *